Extrafloral and floral nectars,
wound sap, and honeydew sources from an Australian rainforest (Cape Tribulation,
North Queensland). Ant attendance was quantified as the number of plants visited
by any ant (total 43 ant species) and by Oecophylla smaragdina in particular.
Floral nectar sources from flowers with narrow tubes (inaccessible to most ants)
were not included in the analysis. Three common floral nectar sources (A.
graveolens, N. normanbyi, S. gustavioides) were not used by ants despite
accessible nectar and although ants were present on the plant (Blüthgen et al. in press). HPLC
results are shown for (a) sugar concentration and composition and (b) amino
acid concentration and composition (for methods, see Blüthgen
et al. in press). Total concentration was calculated on the basis
of identified sugars or amino acids, respectively, and concentrations of single
compounds as per cent of total identified (mean ± SD).
A cross () marks compounds that did not occur in all samples of a source.
Amino acids that were identified in two or more samples, but only occurred in
trace amounts (not quantified) were marked by (+), missing compounds by (-).
All amino acids with mean concentration values given and those with (+) were
coded as being present in the respective nectar source for characterization
of amino acid profiles in NMDS analysis (see text). N = Number of samples/plant
individuals analyzed for sugars or amino acids, respectively.